Dynamics of Growth and Egg Traits in Three Dietary Balanced Protein Scenarios Applied for Laying Hens

Abstract

The objective of this study was to evaluate laying hens from 8 to 102 weeks old, regarding their changes in performance, body composition, and egg components produced in three scenarios of nutrition. Three treatments designed to contain different levels of balanced protein (BP) were randomly assigned to the experimental units, performing ten replicates per treatment with 20 birds each. A standard feed was formulated to meet hen requirements and the ideal ratio between essential amino acids. Then, two experimental feeds were formulated to contain 20% above or below the dietary BP used in the standard feed. The responses evaluated were cumulated feed intake (g), daily feed intake (g/day), body weight (g), body composition (g of protein, fat, and ash), hen-housed egg production (%/hen-housed), egg production (%), egg weight (g), egg mass (g), and egg components (percentages of yolk, albumen, and eggshell). The dietary BP influenced the body composition, egg production, egg weight, and egg mass of white laying hens. The increase in dietary BP was related to an increase in body contents and egg weight, whereas hens consuming the low dietary balanced protein presented a lower body weight, leaner, and produced smaller eggs.

Response of Laying Hens to Repletion and Depletion in Dietary Balanced Protein

“…In this study, the age at sexual maturity (50% of egg production) was influenced by the feed given in the rearing phase, where pullets in the higher dietary balanced protein feed reached sexual maturity approximately 7 days before, which may have elicited an increase in feed intake prior to the laying hens consuming the L feed, minimizing the difference in cumulated feed intake at the end of the rearing phase (18 weeks of age). In fact, the results published elsewhere by Da Nóbrega et al [ 21 ] demonstrate an increase in feed intake due to a reduction in dietary balanced protein, which is minimized when pullets approach 15 weeks of age. According to Bendezu et al [ 22 ], the development of the ovary and oviduct is maximized around 15 to 16 weeks of age, which affects the needs for energy and nutrients and, consequently, feed intake.…”